Dygraphs: provides rich facilities for charting time-series data in R and includes support for many interactive features.

Plotly: translate your ggplot2 graphics into an interactive web-based version.

d3heatmap: creates interactive D3 heatmaps including support for row/column highlighting and zooming.

MetricsGraphics: enables easy creation of D3 scatterplots, line charts, and histograms.